The presence of significant quantities of H.sub.2 S in various "sour" industrial gaseous streams poses a persistent problem. To remove this contaminant, various procedures have been developed. An additional contaminant in many such gases is carbonyl sulfide. In many cases, those processes which remove H.sub.2 S are unsuitable for or deficient in the removal of COS. For example, in conventional solvent absorption-desorption processes, the COS is only partly absorbed, so that recovery is not efficient.
In another cyclic process that is currently attracting attention, sour gas is contacted with aqueous oxidizing reactant solution to convert the H.sub.2 S to free sulfur. In most instances, COS is unaffected by the reactants employed. For example, where such reactant materials as polyvalent metal ions or polyvalent metal chelates in aqueous solution are reacted with the H.sub.2 S, the COS does not react and remains in the gaseous stream. Thus, a need has existed for an efficient process that treats gas streams which contain H.sub.2 S and COS. The invention is such a process.